Working on a ship with only 4" guns. How doable would be modifying a fast gun cannon to fire 1/8th inch bearings? Not as main armament of course. That is a spread of torpedoes, but those are one shot wonders and would like at least the morale effect of a working gun or two.
You would want to work on the breech from scratch. You would need a different O-ring size, barrel, etc. It should work, just that everything will be smaller.
My suggestion for you is to make certain that the method of compressing the O-ring has as fine an adjustment as possible, e.g. fine threads if you are using a threaded fastener. It makes tweaking easier and you have a lower probability that the vibrations from firing will unscrew something. As far as the O-ring, get one that just barely lets the bearing fall through. Then make it sit in a pocket that the O-ring just barely sits in. no resistance to the O-ring sliding in/out but no significant slop, either. hope that helps.
I compress my o ring with the cap/ barrel also. I use blue locktite on the threads and then work it a little with a wrench. It holds fine adjustment and doesn't back off.
It is possible that a standard cannon would work. The O-ring might need to be exchanged for one with a smaller I.D.. And the piston might have to be adjusted up just a hair, as the 1/8" round would be slightly smaller than a BB, and would probably need to sit slightly higher than a BB. I have had cannons de-tweak themeslves, after firing a few times. generally, I found that the o-ring was dry. Mikey
Yep but he might be able to make new barrels out of brake line or something similar. Would it still feed well? I'd worry that maybe you get a double feed that causes it to jam.
The just use a smaller O ring was my first thought. .162 vs. .177 is not that much of a difference but the shot would tend to rattle down a .177 barrel. I had not thought about the problem of a double feed jamming the guns though. These are not going to be killer guns by ANY stretch though.
true, i was thinking ud have a issue like an unrifled musket, and your accuracy would be horrible. And no, they wont be killer guns, but you want them to be respected too, you shoot a ship with a 1/8" gun that works, and youll do more damage then a 1/4" round that wont even roll down the barrel.
I thought you were going for1/8" shot? 1/8" is 0.125 inches.... which is substantially smaller than a BB. You will have to adjust the piston/selector region for the smaller shot. I would recommend perusing mcmaster.com for fittings for smaller tube sizes and tubes. you can get stainless tube in almost any small ID you can image from them.
Accuracy may go down if you use a larger-diameter barrel than your ammunition, but is that really a problem? At the usual engagement ranges I see, I'd personally rather have a scattergun effect than a pinpoint sharpshooter.
The gun/guns are morale support anyway. I have my doubts as to the ability for a 1/8" round penetrating 1/8" armor.
[FONT=Arial,Helvetica,Sans-serif]9452K167 5560K417 9452K318[/FONT] I would recommend starting with parts in the size range of those linked to above... One of those two O-ring sizes will work. Not as certain about the tube I liked to but it should be adaquate, and you can use a tighter tube for the last few inches of barrel depending on the quality of your shot.
While reading some of the back issues of Hullbusters (a fast gun newsletter), there was an account of a battle between big gun and fast gun ships around the mid-90s. The article related the diffrences between the ships and some results of battles between the ships. If I remember right, BBs had no problem penetrating 1/8" balsa armor at fast gun engagement ranges. Remember, fast gun tends to battle at ranges less than 6' and more often within 1 - 2' of the other ship. It might be a lot diffrent at longer ranges.
I ran some penetration tests several years ago, and found out some interesting things. Under ideal conditions, a 1/4" round is perfectly capable of penetrating 1/8" double-silkspanned balsa, at 30 feet, given a perpendicular impact angle and no skipping. Beyond 30 feet, the cannons were simply too inaccurate, and I couldn't land a hit, although the shots themselves still packed a lot of staying power. HOWEVER most big-gunners recognize that thumping away at a target 30 feet away is a waste of ammo. We generally don't open fire until 10 feet, and don't seriously start expecting hits until 6 feet. Obviously, the real "money-makers" are at 2 feet or less, and torpedo-cruisers engage at 6 inches or less. Under these conditions, the foam test starts to tell. With the foam test, at 12", cannons of all calibers have nearly identical penetration characteristics. The difference between calibers, then, is how well they carry their energy through air and water. Larger-caliber projectiles carry their energy much better, and can thus penetrate well at longer ranges, as well as score a higher percentage of red hits. Smaller-caliber shots can penetrate just as well at point-blank range, but don't have the mass to carry their energy long distances. Furthermore, larger-caliber hits leave bigger holes, which flow more water. Thus, fewer large hits are needed than small hits in order to sink a given opponent. Interesting how history translates to the models, huh? Personally, I would be very interested in a Big Gun vs Fast Gun match. My only concern is the speed difference. If we could somehow agree to a set of speed rules that's fair for both combatants, I think it could be a great match.
